Line items
Mediation line items are individual monetization strategies. Line items are where you define the order to call each ad network, the pricing strategy at each level of the waterfall, and other related criteria.
On the Waterfalls page, you can create a line item to define your individual monetization strategies. You can add bidding line items, eCPM line items, and Auto-eCPM line items.
We've found that the best way to maximize revenue is to leverage both Bidding and Sort by eCPM Targets for each network. To learn more about how to set eCPM prices and adjust them as needed, see Hybrid waterfall solution.
On the Waterfalls page, you can also select a waterfall name to view the Waterfall Detail Report. Use this report to review the performance of line items in closer detail to make operational changes.
Bidding
Unlike when you set an eCPM target line item or Backfill line item, you can set up a bidding source and bidding line item to participate in an equal-opportunity competitive auction. For more information, see Bidding and Placements and eCPM targets.
Sort by eCPM target
A line item in this section maps to a configured ad source and an eCPM target, which determines the line item’s order in the waterfall. Ad Sources are called based on the sort order of the eCPM target, and if the ad request does not receive a response, the waterfall moves to the next line item.
Note: The eCPM targets you set for ad networks other than Unity only dictate the priority in which they are called in the waterfall. Ensure that you mirror the eCPM targets in the Unity Dashboard with actual floor values in the third-party ad network platforms.
We recommend that you set different targets for each line item in the waterfall, because line items with the same eCPM target are prioritized in the order that they were created. For example, if you create a Unity Ads line item for $10, and then a $10 AdMob line item, the Unity Ads line item is called first, followed by the AdMob line item. However, the practice of setting the same eCPM value for multiple line items is discouraged so you have greater control and oversight across your line items.
Auto-eCPM (Backfill)
If no ad source meets its associated eCPM target, the line items in this section exist as backfill to pick up any unfilled impressions to capture opportunities when there are no other higher priority line items available.
Note: When you create backfill line items, you can only have one line item for each Ad Source.
You do not need to set an eCPM target for auto-eCPM line items because they optimize based on the last 24 hours of historical eCPMs by ad source.